Werner, a campaign strategist at Public Citizen, is attending the hearing where Facebook founder Mark Zuckerberg is testifying to draw attention to the social network's failure to stop the misuse of its site during the 2016 presidential election.

Zuckerberg "confirmed that Russian troll farms reached 126 million Facebook users," Werner said in a statement. "Since Zuckerberg allowed millions of Russian trolls to undermine our democracy, I assume he won't mind if one Russian troll undermines his credibility."

Last year, Werner dressed as the Monopoly man and sat behind former Equifax CEO Richard Smith during his Senate hearing. Then, she was protesting common industry rules that force consumers to settle disputes with financial companies in arbitration rather than court. Smith was testifying about Equifax's massive data breach affecting more than 145 million people.

Zuckerberg is on Capitol Hill this week to answer questions about the data leak affecting 67 million Facebook users. Werner told CNBC in a direct message on Twitter that her costume was definitely drawing attention on the Hill, where a police officer told her to remove her headscarf.